By Gregor Paul in Dublin
It was against Ireland, in 2012, that Beauden Barrett made his All Blacks debut, impressing everyone with his composure and maturity and surprising himself with his defensive contribution.
Back then Barrett, by his own admission, wasn't much of a tackler. His defence was a weakness. He was a bit passive in the art of bringing players down, more of scragger than a thumper and it was that as much his supreme ability to impact games off the bench at fullback that restricted him to just six starts at first-five between 2012 and 2015.
"It was the highlight of my career," Barrett said of his debut, which came in a near unthinkable 60-0 drubbing of Ireland.
"The first opportunity to wear the black jersey. I remember coming off the bench feeling like superman, making tackles I had never made before. I couldn't tackle back then. It just gave me a wonderful sense of power."
Looking back now the transformation in Barrett has been enormous. He doesn't have the same ability as England's Owen Farrell to make jarring, destructive tackles, but Barrett is one of the best defensive first-fives in the world game.
He's a great tackler now, all shoulders and leg drive and how well he defends such a critical channel is often not fully realised.
In the past few years Barrett has made endless try-saving tackles. Everyone remembers the way he chased South Africa's Willie le Roux and caught him in the corner in 2013, but he's made many more head-on, high impact tackles since then.
One of the more significant was the last time the All Blacks were in Dublin. Six minutes in and Irish loose forward Sean O'Brien was played into a hole on the edge of the ruck by No 8 Jamie Heaslip.
He was at full speed, almost unstoppable and yet Barrett got back to the bigger man and was strong enough to not only bring him down, but turn him in the process to prevent the try being scored.
Those sort of brave, effective, almost dominant tackles are a staple of the Barrett repertoire these days and from once being vulnerable he is now one of the most reliable and consistently good defenders in the All Blacks.
And this hasn't come about by chance. Of all the things Barrett was asked to work on in his early All Blacks career, defence was somewhere near the top.
There was ample faith in his ability to convert an incredible attacking skill-set into a polished all-round tactical game.
The All Blacks coaches could see that they had something special and that with time in the role, Barrett would be one of the best offensive first-fives in history.
But modern rugby demands that a No 10 must be willing and able to play without the ball as much as with it.
The channel manned by the No 10 is rugby's equivalent of the Suez Canal – the preferred route of the big tankers and they won't deviate if they suspect they can smash over the top of a smaller vessel.
And if they can do it, the game is up – which is why Hansen sat Barrett down early in his career and made it clear that the All Blacks need a defensive rock at No 10.
"You have to grow that area of your game," says Barrett. "You don't want to be a weak link in that transition zone otherwise teams will target you every strike move.
"It was an area I had to work on and focus on and Steve [Hansen] made it obvious for me so I worked hard on it. You have to grow into your body and I was quite young back then and I didn't feel strong and confident. I think that was part of it too.
"It gets me into the game when you are forced to make a few tackles early on and it gets you in that right head space."
Six years since making his debut, Barrett is almost unrecognisable as a player and he surprises more than just himself with how many tackles he makes.